It is often desirable to accurately measure the distance between two objects. It is also often desirable to be able to map the surface of an object, i.e. to measure surface deformations or protrusions on the surface of an object. These tasks become increasingly difficult when working with nanoscale objects. For example, a distance that is difficult to measure is the “fly height” between a slider, or protrusions on the slider, and a disc positioned adjacent thereto. In addition, it is difficult to measure the protrusions on the surface of the slider.
Slider/disc arrangements are commonly used, for example, in data storage systems. Increased storage density is becoming increasingly important and a reduced fly height allows information to be stored in a smaller area, i.e., at a higher areal density. As fly height dimensions continue to decrease to support increased storage densities, it is important to be able to accurately measure the fly height and any protrusions on the surface of the slider in order to ensure that the data storage system is operating as designed.